Humans 1, Robots 0

Cashiers Trump Self-Checkout Machines at the Grocery Store

Computers seem to be replacing humans across many industries, and we're all getting very nervous.

But if you want some reason for optimism, visit your local supermarket. See that self-checkout machine? It doesn't hold a candle to the humans—and its deficiencies neatly illustrate the limits of computers' abilities to mimic human skills.

The human supermarket checker is superior to the self-checkout machine in almost every way. The human is faster. The human has a more pleasing, less buggy interface. The human doesn't expect me to remember or look up codes for produce, she bags my groceries, and unlike the machine, she isn't on hair-trigger alert for any sign that I might be trying to steal toilet paper. Best of all, the human does all the work while I'm allowed to stand there and stupidly stare at my phone, which is my natural state of being.

There is only one problem with human checkers: They're in short supply. At my neighborhood big-box suburban supermarket, the lines for human checkers are often three or four deep, while the self-checkout queue is usually sparse. Customers who are new to self-checkout might take their short lines to mean that the machines are more efficient than the humans, but that would be a gross misunderstanding.

As far as I can tell, the self-checkout lines are short only because the machines aren't very good.

They work well enough in a pinch—when you want to check out just a handful of items, when you don't have much produce, when you aren't loaded down with coupons. But for any standard order, they're a big pain. Perversely, then, self-checkout machines' shortcomings are their best feature: because they're useless for most orders, their lines are shorter, making the machines seem faster than humans.

In most instances where I'm presented with a machine instead of a human, I rejoice. I prefer an ATM to a flesh-and-blood banker, and I find airport check-in machines more efficient than the unsmiling guy at the desk. But both these tasks—along with more routine computerized skills like robotic assembly lines—share a common feature: They're very narrow, specific, repeatable problems, ones that require little physical labor and not much cognitive flexibility.

Supermarket checkout—a low-wage job that doesn't require much training—sounds like it should be similarly vulnerable to robotic invasion. But it turns out that checking out groceries requires just enough mental-processing skills to be a prohibitive challenge for computers. In that way, supermarket checkout represents a class of jobs that computers can't yet match because, for now, they're just not very good substituting key human abilities.

What's so cognitively demanding about supermarket checkout? I spoke to several former checkout people, and they all pointed to the same skill: Identifying fruits and vegetables. Some supermarket produce is tagged with small stickers carrying product-lookup codes, but a lot of stuff isn't. It's the human checker's job to tell the difference between green leaf lettuce and green bell peppers, and then to remember the proper code.

"It took me about three or four weeks to get to the point where I wouldn't have to look up most items that came by," said Sam Orme, a 30-year-old grad student who worked as a checker when he was a teenager.

Another one-time checker, Ken Haskell, explained that even after months of doing the job, he would often get stumped. "Every once in a while I'd get a papaya or a mango and I'd have to reach for the book," he said.

In a recent research paper called "Dancing With Robots," the economists Frank Levy and Richard Murnane point out that computers replace human workers only when machines meet two key conditions. First, the information necessary to carry out the task must be put in a form that computers can understand, and second, the job must be routine enough that it can be expressed in a series of rules.

Supermarket checkout machines meet the second of these conditions, but they fail on the first. They lack proper information to do the job a human would do. To put it another way: They can't tell shiitakes from Shinola. Instead of identifying your produce, the machine asks you, the customer, to type in a code for every leafy green in your cart. Many times you'll have to look up the code in an on-screen directory. If a human checker asked you to remind him what that bunch of the oblong yellow fruit in your basket was, you'd ask to see his boss.

This deficiency extends far beyond the checkout lane.

"In the '60s people assumed you'd be reading X-rays and CT scans by computers within years," Mr. Levy said. "But it's nowhere near anything like that. You have certain computerized enhancements for simple images, but nothing like a real CT scan can be read by a computer—and the same thing would be true trying to separate arugula from everything else."

You could imagine certain ways to make the identification process easier for supermarket computers. For example, we could tag every produce item with an electronic identification tag. But that would be an enormous infrastructural challenge for a dubious return.

A representative for NCR, the world's largest self-checkout vendor, pointed me to a company-sponsored survey that shows that customers believe self-checkout systems are faster than cashier lanes. But I doubt those perceptions. When you actually watch self-checkout lanes matched up against cashiers, the cashiers come out significantly faster—read this Ph.D. thesis for proof, or go to your local store and marvel at how speedy the humans are.

Can computers beat them? Perhaps one day, but I doubt it will be soon. And that gets to the other issue: Unless the store gives me an explicit price break for scanning my stuff, why, exactly, should I be rejoicing about doing more work?

—High Definition is a twice-weekly column about technology issues, people and companies.

"At my neighborhood big-box suburban supermarket, the lines for human checkers are often three or four deep, while the self-checkout queue is usually sparse. "

It's the opposite at mine. Which of our anecdotes is more accurate?

I think the key thing this article overlooks is exception handling. When some something unexpected occurs, the automated checkout relies on a human backstop. And this works.

The problem I have seen more frequently is that the human customers cause the most problems. They continually tie up automated checkouts with their incompetence and sloth. There should be a test before you are allowed to use them.

Even worse, the automated bottle return machine. I went there today with my aunt. She's 79 and special needs, she collects the bottles from around the house, porch and (I suspect) the neighbors trash. I bring her down there and she collects the money.Half an hour feeding bottles and cans into that pig, Every other one is rejected and must be fed back in, again and again. She enjoys it, I don't. Until finally we end up with about 10/15% that just can't be read.

After ringing for the human attendant and waiting, he arrives, glances at the unreadable's, punches some numbers into a machine which prints out a slip that he hands us. Elapsed time, 20 seconds.

The machines are great. The human labor they replace is low-skill drudgery that needs to be squeezed out of society. We don't need that. Worker aspirations need to aim higher. If we could automate burger flipping, retail, and other low-skill wastes of time, so much the better.

I purposely favor the automated checkout lines, ATMs, and other innovations as soon as they are deployed. After all, someone has to spend money to offset those with a technology phobia. I vote with my wallet, and I vote alot. I suspect that what I spend offsets 5 luddites who avoid the technology. I look at it as if I'm paying Luddite Offsets. We gotta reduce the effect of the Luddites in the economic "environment". Be responsible, support progress.

I have used self checkouts a number of times; ones in super markets have not given me a problem. This does not mean I like them; I prefer the human interaction that takes place at a staffed checkout line. The primary problem that I have had with self-checkout was in Home Repair stores where I had a buggy full of lumber and the register did not have an auxiliary scanner; this was okay except where the bar code was stamped on the lumber, rather than a tag.

As to groceries, I have had no problems finding the items in the lookup. I know what the items are in my buggy, so the little tags are not important. I would never put something in my buggy that I cannot identify at the register, either by knowing what it is or writing down what it is, so there is no problem with the checkout. The self-checkouts that I have used have all included the ability to tell the register that you were not going to put the item in the bag, so that was not a problem, as it was on some of the original units.

For that one in a thousand item that is not in the system, it really takes no more time for the one "overseer" to help me get a code than it does for a traditional "price check".

All in all I have been happy with the self checkouts; they are certainly better than standing in the "10 items or less" line when the person in front of you has a buggy full, and the store will not tell them to move!

Self checkouts are great assuming that your purchases have easily recognizable bar codes, do not exceed the maximum size area on the scale where scanned items wait to be bagged, do not require proof of age (some OTC medications), and do not require coupons. Small orders tend to work well, but awkwardly shaped/over sized items tend to gum up the works, especially at places like Home Depot.

One place that I have seen a great implementation of automated machines that replace humans is at the US Post Office. The machines weigh, print postage, and give you all of the options that the postal worker at the end of the twenty deep line can give you, all without the snarky attitude and long wait times. Even simple trips to buy stamps go faster with these machines.

Article ignores the perception of time. When I'm watching someone else checking my groceries over 1 minute feels like an eternity and I want to pull my hair out and punch the employee in the face. When I'm checking my own groceries out, 3 minutes feels pretty quick. I'll take the machine every time.

I refuse to use self-checkout. People need jobs & the more we utilize the machine vs individual, we promote & encourage big business to lay off more people & install more machines. I, for one, want no part of this. Even though these jobs aren't the highest paying, I applaud the individuals who work as cashiers since it would be just as easy to stay home & collect a welfare check....but, instead they choose to have self-respect and work and rise above easy government handouts.

RFI tags will eventually eliminate all checkout lines. You won't need to checkout because your shopping cart will log the stuff as you take it off the shelf and put it in, and when your cart passes out of the store the items will be confirmed as bought and your account will be charged - or an alarm will sound.

I personally love talking to the checkers, especially at my market where I know them all. I wouldn't think of using a self-checker simply because it's not fun. Talking to the checkers is fun! And they bag my stuff too!

The mismatch occurs once you get outside the store, too. Is it just me, in sometimes selfish Southern California, or have others noticed the increasing unwillingness of people to return their shopping carts to the numerous bays for them scattered around the parking lot? No computer can take care of that problem, but there are at least two humans who can do so: the shopper who abandoned it and the lowly stockboy who's tasked with policing the lot. And, of course, the occasional Good Samaritan who makes a habit of returning these traffic and safety hazards to their rightful place.

Basically, the self checkout is the same as the staffed lines, except they turned the line around. You the customer are also now the checker. I use them when I don't have much to get, but for a full basket, head for the staffed lines.

i bought a single item at Home Depot and thought the self-check would be quicker. Unfortunately, I also brought in the item I was replacing to match it with the new one and put that in the bag at checkout. The computer noticed that the bag weighed twice as much as it should and sounded an alert for an employee to verify my purchase. That added about 5 minutes to my checkout time waiting for help.

Like many, I used the automatic checkouts when they first came out, and have for awhile. Then it occurred to me to practice what I preach about labor, labor gluts, and the rise of automation in displacing human workers. So now I avoid them, and make sure I tell the checkout clerks as well as management why I don't use them.

Same thing for ATMs, although I do use those about 50% of the time, and am trying to wean myself off of them.

The time spent waiting in line, I can just play with my phone or talk to people.

I dasagree with the author. Self checkout is always faster than waiting in line for a checker. Most people in this area must agree because they keep six self checkout lines humming while the two staffed check stands help the elderly or those with limited technical skills.

The point is not whether the machine or the human wins (after all, even the computer lines require one human for six machines), but that there is a choice by the consumers to pick which service works best for them, based on their preferences and what they happen to have in their cart.

BTW, based on my own observations, there are apparently large differences between local market preferences. I am guessing the writer is located in a metro area and in socio-economic market where people are used to a high level of personal service. I assume this may be the reason that his observations are so much different than mine out here in the more rural sort of areas where human powered check outs seem to be mostly for the elderly and those with overflowing shopping carts. Otherwise it seems that customers only go to the humans when the machine line is full.

There also seems that there needs to be some level of honesty in order for the automated lines to operate efficiently as it seems that enterprising sorts would seem to be able to cheat such systems with a modicum of effort. I wonder if such systems are workable in areas where security is a concern.

So, if I feel the need to have someone indifferently pack my bread securely beneath my gallon of milk because I am too involved in tweeting my feelings about my shopping experience to attend to such mundane activities myself, I will certainly consider the use of the full service line.

I use the self check at the unionized store in town, and a manned lane at the customer friendly non union store. I tired long ago of louse noting to the whiners talking about how long it was to their next break.

Without exception until my last check out, I've needed to have the clerk overseeing the self-check out area of my local supermarket come and help me complete a transaction, often more than once, for all sorts of reasons.

I succeeded last time without any human intervention (other than me) so I went up to the clerk to share my success and asked if I could get some kind of recognition like a diploma or a brownie. He said "no."

I asked if he could announce my achievement over the store's public address system. He said "no."

So the only thing a self-checkout can't do that a human can is identify produce? That means if one is not buying produce, then the only superiority is gone. Sorry, but humans are *not* always faster, certainly not all more pleasing (a subjective assessment), and they do not all bag your groceries (and when they do, they may do things you don't want like putting ice cream in the same bag as bread). And while they may not be on "hair-trigger toilet paper alert, just give them a fifty-dollar bill and watch the proof pen come out. Or hand them a coupon and wait for them to verify that you did, in fact, buy two of the right kind of yogurt.

The only way a human is better than a self-check is if you're the type that values human interaction. Since the author's main complaint is that he has to pull his nose out of his phone for five minutes, fondness for humans is clearly not at work here.

I love self-checkouts. In my experience, they are quicker and more convenient for me when I shop. I use search to type in the names of produce, and rarely, if ever, have any problems. Perhaps the author needs more practice.

Every self checkout I have used has item lookup by name and picture. Sure I can punch in the code if I record it, but I can type the word "tomato" far more easily. And there is always a handy employee running a group of self checkout counters in case there are any issues.

For those who don't know how to use the self-check out, sucks to be you. I love it. I know when to use and not use. If you have alcohol or lots of produce, use the human. If you don't and it's all UPC, you can fly through it faster than a human all day, any day. I'll take time saved as my discount. No sour grapes here!

Mr. Manjoo once again takes journalistic license in precedence over good interviews. I'll state my credentials: I'm a mature man who worked for more than four years for TJs, a symptom of my underemployment in my field.

A few things stand out about FM's comments. There are longer lines for human cashiers not because there are not enough people to fill those jobs, but because most (TJs is an exception) grocers find it too expensive to hire enough people to do the job. Robot cashiers are very cheap, and while untrained humans are slow at scanning items and processing payments, the compensation of autonomy is enough to offset the perceived problem.

It would be simple enough to create a system with, say, RFIDs, that would be far more efficient for robot cashiers, but grocery stores don't operate on efficiencies as much as they do on margin. It's okay if someone miscounts the bananas, and the presence of stupid robots works in the store's favor - if you don't place your product in exactly the right place, you'll be punished by waiting for the single employee servicing 6 or 10 registers (Fresh & Easy seems to have the outside limit here, but Home Depot runs a close second).

So the human cashiers have already lost and, if RFIDs drop in price, humans will be using their now-diminished foodstamps (or a very limited amount of cash) to buy things at a store whose humans have mostly been replaced.

You don't have a strong password on your ATM because the balance between you being pissed-off for having to remember a long/strong password, and the loss the bank suffers due to broken, solved, or stolen passwords is smaller than the cost to provide you with better security. A similar thing is happening with your robot cashier.

I like self-check-out. But I just shop for myself, and seldom have more than 2 bags of groceries at a time. And over time I have learned the 4-digit codes for produce items that I regularly purchase. Kinda funny that once I knew all my friends' phones numbers (lots of 7-digit numbers), but now rely on a "contact" list to do that for me.

It would be easy to scan a head of lettuce and place it into a shopping bag along with an unscanned small piece of fresh ginger, but I wouldn't.

In Spain the opposite holds true. The painfully slow cashiers that don't bag your groceries or have any consideration for the 10 people in their line are a clear example of how the self checkout is superior in some places. Imagine the pace of a checkout line if everyone in that line were paying by check and had severe Parkinson's...that's Spain.

A while back, my bank clerk saw me have many deposits to do every week and notified one of the bankers. I got a call from that banker guy telling with an exciting voice about first 6 months free using a scanner to deposit electronically from my office.

Before he could finish, I asked after 6 months, how much I am going to be paid by you since you are trying to hire me do the deposits for you. He was so shocked and seriously telling me that actually after that there will be a monthly fee we charge YOU for using our devices.

My response is so you think me a business owner would take upon a deal where I will have to pay somebody to work for that somebody. He laughed, the end!

I could not disagree more. Stop & Shop offers price guns that allow the shopper to tally and bag their items as they go around the store. At the end you scan a bar code at the self-checkout line, pay and leave. It takes about one minute.

With that line of morality, I assume you don't use a refrigerator, as that would cost the iceman his job. Or drive a car, since that put the stable boy and farrier out of work. Don't drive through electronic traffic lights to ensure traffic cops remain in demand. Don't use a vacuum as that would put the maid out of work. Don't fly internationally as that would put the cruise ships out of work. And by all means, don't use a cell phone, since the telegraph man needs to stay employed. The list goes on, ad nauseam.

Sure is! Lower prices draw customers to stores. The first store to install it gets to enjoy higher profits. When the second store installs it and lowers prices, they force the competition to do the same.

2nd- the jobs for automated checkout builders and repairmen are better jobs than cashier jobs!

Fully agreed. My experience has been the exact opposite of that of this author. The only problems that I have ever had are from having to wait behind someone who has no clue how to use the machine. (A person who probably still has a VCR, with the clock flashing 12:00AM.) A cashier may be faster for the average consumer, but not for someone with enough technical understanding to work their way through a very simple user interface in the case that a "non-normal" event occurs.

It is not about "don't know how". I know how to do a lot of things at work as a business owner. Hell no, I am not going to pick up the phone, file records, receive shipments, or shipping out. It is all about who is supposed to do, not able to do or not for vast majority of people anyway.

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